Apparatus for and method of feeding sheets



June 7, 1932. E. c. MAASS APPARATUS FOR AND METHOD OF FEEDING SHEETS,

Filed Oct. 29, 1929 l tf 1 INVENTOR; E'wrlsi; C ,Maass',

ATTOR EY Patented June 7, 1932 ERNEST C. MAASS, OF GREAT NOTOH, NEW JERSEY APPARATUS FOR AND METHOD or rename SHEETS Application filed October 29, 1929. Serial No. 403,150.

This invention relates to apparatus for and method of feeding sheets and especially of the class whereby the sheets are one after another removed from the top of a sheet stack and each then delivered edgewise. Where the sheets are of flimsy material and especially where they have fibrous projections which will interlock their-"surfaces, as sheets of certain qualities of paper or the like fibrous material, it has heretofore been impossible to accomplish the separation in the intended manner, to wit, one at a time and not occasionally more than one at a time. One object of this invention is to provide for the separation of the sheets unerringly one by one although such separation, with the delivery of the sheets, may be carried on at very high speed. Another object is to provide for the delivery of the sheets successively by simple mechanism, rapidly and with precision to the place where they are intended to be delivered.

In the drawing, a m

Fig. l is a side elevation illustrating the invention more or less diagrammatically:

Figs. 2 and 3 are fragmentary side elevations on a larger scale of certain parts appearing in Fig. 1 and illustrating more or less diagrammatically how the sheets are separated; and

Figs. at and 5 are a front elevation and a plan of means active in eflecting the separation of the sheets.

Let 1 designate a suitable .base and 2 a support supported thereon through the medium of elastic means, as a spring '3, being here pivoted to the base rearward of the spring on a horizontal axis, as the pintle 4;. This support carries the stack of sheets A one of whose end faces, afforded by one end sheet (here its top face), is exposed Thus the stack is so supported that each time a top sheet is removed the top of the stack assumes its previous level, at least at its forward (here right) side.

6 is a detent here consisting of an up standing piecegof sheet metal fixed at its lower end (as between support 2 and an upright wall 5-secured thereto) and curved orbent rearward, its upper edge portion being formed with (here) three rearwardly bentoft' lips Ga and (3b, lip 6a bein higher and extending further rearward t an the two lips 66 between and spaced from which it is arranged. The stack A, having the rear edges of its sheets abutted by a spring blade 1awhich holds the front edges thereof pressed against tLe detent 6, is arranged on the support with its front side under the abutments formed by the lips 66 and inthe 00 present example actually clamped between these abutments and the support 1 due to the action of spring 3.

Means for transferring the sheet from the stack to a definite place, as to the nip of a 0:; pair of feed rolls 7, here comprises a carrier in the'form of a lever 8 fulcrumed at 9 on an axis parallel with the sheets and an adhcsion device here in the form of a lever 10' pivoted thereon at 11, such device having one end vdirecteddownwardly and equipped with an'adhesion element, as an elastic, yielding (as soft rubber) inverted suction-cup 12. This transfer means is moved backward and forward by the coaction of a rotating cam 13, acting on a roller 8a of carrier 8, and a spring 14 connecting the carrier with some fixed point, as 15, and holding the roller -against the cam. 'When said means is being moved by the cam (or so as to depress the suction cup) a spring 16, connecting device 10 with some fixed point, as 17 tends to hold said device with a pin or the like 18 thereon against a part of the carrier as a stop, which it actually does in the latter part of this (downward) movement of said transfer means, so that the suction cup will come to exert the necessary pressure on the top sheet of the stack to form a hermetic seal between the cup and said sheet. When the transfermeans is being movedby the s ring (14), or so that the suction device rece es from the stack, the adhesion device encounters a stop 10a which'shifts said device on its fulcrum and relatively to carrier 8 so that the suction cup advances toward the feed rolls. -The cam 13'is of such form that between each two succeeding down and back movements imparted to said transfer means the latter is held at dwell to insure the sheet I received by'the feed rolls,

' the sheets) such begin on (or being received in picked up and carried to the feed rolls being advanced clear of the stack before said transfer means returns to the stack, this dwell here corresponding to somewhat more than one-half of the cycle of rotation of the cam. The cam and one feed roll are geared together so that in a cycle of the cam a sheet started on its progress by the feed rolls will be discharged therefrom, to wit, by a gear 19a fixed on the cam and meshing with a pinion 19?) having a gear 190 in.mesh with a pinion 19d revoluble on the axis of the cam and having a sprocket-and-chain connection 19 with said feed roll.

The suction is here obtained froma pump 20 of the reciprocatingclass, the working space formed by its cylinder being connect-- ed with the suction cup by a flexible tube 21 and its piston being connected by a pitman 22 with a wrist-pin 23a on the pinion 23 in mesh with the gear 19a. The suction should slightly before) the return or receding stroke of said transfer means (the position of the parts illustrated in full lines, Fig. 1) and it should terminate on the sheet the nip of the feed rolls, wherefore the gearing 23-19a has the gearratio of 1-2; in this example, and by preference, following each suction interval pressure is established in the cup so as to discharge the sheet from the cup on its being and this is obtained from the pump on each pressure stroke. (Due .to"the mentioned gear-ratio between the gears 2324 the pump performs two back and forth strokes for each cycle of the cam, but one of these is idle and immaterial since it occurs after the sheet has been discharged from the cupthen at dwell-and while it is still under the advancing influence of the feed rolls).

In general, then, the operation of the trans fer means for delivery of the sheets from the stack A to the feed rolls consists in its moving back and forth, in one direction to position the suction cup in adhering contact with the top of the stack and in the other to carry the sheet picked up to the feed rolls. But in particular, and having reference to the separation of the sheets so that one and one only will be picked up and removed from the stack by the transfer means: The suction cup portion of said means, due hereto the movement of the latter on its fulcrum 9, moves initially (in an are a, Fig. 1) so that there is some rearward progress of the cup when it rises, with the effect of drawing or slipping the top sheet from under and thus clear of the abutments formed by lips 66 (Fig. 2). If in this operation the second sheet is 'also slipped out (due to fiber-interlock between condition is attended by sufficient incidental slippage of the top sheet relative to the second sheet so that their forward edges become stepped, as in Fig. 2, the

forward edge of the second sheet being in advance of that of the first sheet. Therefore when the top sheet is carried up by the suction cup against the stop or catch formed by the lip 6a, and if the second sheet still adheres to and follows with it, this step-formation permits said stop or catch to catch and hold the second sheet (Fig. 3), breaking flimsy, the sheets are taken from the stack one andonly one at a time.

Having thus fully described my invention what I claim is:

1.. In combination, means to support a stack of sheets with one end face exposed, a lever having its fulcrum axis extending substantially parallel with the sheets, an adhesion device movable on the lever crosswise of said axis and also with and by the lever against and adapted to adhere to the sheet of the stack affording said exposed face and also with and by the lever from the stack, means to oscillate the lever on its fulcrum, and means to move said device on the lever first in one direction and then inthe other on the movements, respectively, ofthe lever first in one direction and then'in the other.

2. In combination, means to support a stack of sheets with one end face exposed, a lever having its fulcrum axis extending substantially parallel with the sheets, an adhesion first in one direction and then in the other on the movements, respectively, of the lever first in one direction and then in the other.

3. In combination, means to support a stack of sheets with one end face exposed, a lever having its fulcrum axis extending substantially parallel with the sheets and also having a stop, an adhesion device pivotally movable on the lever crosswise of said axis and normally held against said stop and while so held being also movable with the lever against and adapted to adhere to the sheet of the stack aifordingsaid exposed face and being also movable with the lever from the stack, means to oscillate the lever on its fulcrum, and means to move said device pivotally on the lever and from said stop when moved thereby from the stack.

4. In combination, means to support a stack of sheets with one end face exposed, a carrier movable toward and from said end face of the stack, an adhesion device movable back and forth on the carrier crosswise of the movement thereof toward and from the stack and adapted to adhere to the sheet of the stack affording said exposed face when the carrier moves toward the stack, and means to move said device on the carrier first in one direction and then the other on the movements, respectively, of the carrier first in one direction and then in the other.

5. In combination, means to support a stack of sheets with one end face exposed, a carrier movable toward and from said end face of the stack and having a stop, an adhesion device movable back and forth on the carrier crosswise of the movement thereof to ward and from the stack and normally held against said stop and while so held being movable with the carrier against and adapted to adhere to the sheet of the stack affording said exposed face, and means to move said device from said stop when the carrier moves from the stack.

6. In combination, means to support a stack of sheets with one end face exposed, an abutment to bear against the sheet affording said end face and at an edge portion of such sheet and coacting with said means to clamp the stack, and transfer means movable to and from said end face of the stack and having a sheet adhesion device moving therewith and also confined to move toward the opposite edge portion of the sheet when said device moves with the transfer means from the stack and while the stack is clamped between the supporting means and said abutment.

7. In combination, means to support a stack of sheets with one end face exposed, an abutment to bear against the sheet affording said end face and at an edge portion of such sheet and coacting with said means to clamp the stack, transfer means movable to and from said end face of the stack and having a sheet adhesion device moving therewith and also confined to move toward the opposite edge portion of the sheet when said device moves with the transfer means from the stack and a catch device projecting toward said opposite edge portion of said sheet and spaced from said end face of the stack and adapted to engage the first-named edge of said sheet when the latter is being moved from the stack by the transfer means.

8. The method of feeding a sheet from a stack of sheets which consists in sliding, an end sheet of the stack upon the next adjoining sheet and obtaining an. adhesive grip on the exposed face of the first sheet and thereby and thereupon moving the sheet from the stack in a path angularly related to the sheets of the stack and so as to cause that edge thereof which is relatively rearward when the ERNEST o. 'MAASS. 

